The major objective of the proposed research is to investigate, in comparative perspective, patterns, and determinants of marital instability among Mexican Americans in the Southwestern United States. The research has the following specific aims:(1) to ascertain the prevalence of marital instability among the self-identified population of Mexican Origin: (2) to identify and estimate the magnitude of the effects of demographic and socioeconomic determinants of marital dissolution; (3) to analyze changes in the incidence of marital instability that occurred between 1960 and 1970 among the Spanish surname population; (4) to carry out a comparative analysis of degree of instability among Mexican American, Black, and Anglo families with special attention given to identification of factors affecting patterns of marital disruption within each of the subpopulations as well as to specification of variations in the form of the relationships observed; and (5) to assess the predictive validity of three alternative hypotheses in accounting for differentials in relative levels of marital instability in each of the three groups. The data source is the 1/100 Public Use Samples for 1960 and 1970. All ever married Mexican American and Black persons, 14 years of age and older, together with a ten-percent sample of the analogous Anglo population, will comprise the sample. Subsequent to utilizing a standard multivariate contingency design, a linear weighted least squares model for use with categorical data will be applied to the data. A second methodological technique will involve the use of dummy variable multiple regression. Both procedures permit the estimation of the main effects of independent variables net of the influence of other factors, as well as the detection of interaction effects.